Derivan Cracking Medium lets you produce works that have that weathered look. To obtain a crackled look with Derivan Cracking Medium, there are three steps and three layers involved. The first coat of paint laid down will be the colour that shows through as the cracks. This first coat should be a water-based paint such as Matisse Structure paint or, for larger areas Mattise Background colour will give the best results. Leave this coat to dry before going to step 2.
Once step 1 is dry, apply Cracking Medium. You can use a brush, sponge applicator or roller (either a sponge or short nap roller). Apply the Cracking Medium so that it is as thick as possible but not so thick that it runs when the surface is held vertically. The Cracking Medium is designed to be a high-build coat; therefore, it is very viscous (thick). Do not be overly concerned with obtaining an even flat surface as the Cracking Medium has a built-in flow agent which will allow it to level out as it dries.
This is the coat that cracks to reveal the coat applied in Step 1. Step 3 must be applied within 12 hours of step 2 drying.